We can then extend \({\cal E}^{(c)}\)  uniquely to \({\cal F}\) .
Moreover, for each \(u\in {\cal F}\) ,
there exists a positive Radon measure \(\mu _{\langle u\rangle }^{c}\)  on \(X\) 
such that \({\cal E}^{(c)}(u,u)=\mu _{\langle u \rangle }^{c}(X)/2\)  ([1]}).
